HIP6301

FN4765 Rev 6.00

Page 14 of 17

December 27, 2004

n = the number of channels

Example: Using the previously given conditions, and

n= 4

As discussed previously, the voltage drop across each Q2

transistor at the point in time when current is sampled is

HIP6301 ISEN pin. This pin is held at virtual ground, so the

current into ISEN is:

Example: From the previous conditions,

= 100A,

= 25.49A,

= 4m



= 2.04K and

Channel Frequency Oscillator

The channel oscillator frequency is set by placing a resistor,

to place this resistor next to the pin.

Layout Considerations

MOSFETs switch very fast and efficiently. The speed with

which the current transitions from one device to another

causes voltage spikes across the interconnecting

impedances and parasitic circuit elements. These voltage

spikes can degrade efficiency, radiate noise into the circuit

and lead to device overvoltage stress. Careful component

layout and printed circuit design minimizes the voltage

spikes in the converter. Consider, as an example, the turnoff

transition of the upper PWM MOSFET. Prior to turnoff, the

upper MOSFET was carrying channel current. During the

turnoff, current stops flowing in the upper MOSFET and is

picked up by the lower MOSFET. Any inductance in the

switched current path generates a large voltage spike during

the switching interval. Careful component selection, tight

layout of the critical components, and short, wide circuit

traces minimize the magnitude of voltage spikes. Contact

Intersil

for evaluation board drawings of the component

placement and printed circuit board.

There are two sets of critical components in a DC-DC

converter using a HIP6301 controller and a HIP6601B gate

driver. The power components are the most critical because

they switch large amounts of energy. Next are small signal

components that connect to sensitive nodes or supply critical

bypassing current and signal coupling.

The power components should be placed first. Locate the

input capacitors close to the power switches. Minimize the

and the power switches. Locate the output inductors and

output capacitors between the MOSFETs and the load.

Locate the gate driver close to the MOSFETs.

The critical small components include the bypass capacitors

for VCC and PVCC on the gate driver ICs. Locate the

the device. It is especially important to locate the resistors

associated with the input to the amplifiers close to their

respective pins, since they represent the input to feedback

should also be located next to the associated pin. It is

respective terminals of the HIP6301.

A multi-layer printed circuit board is recommended. Figure 11

shows the connections of the critical components for one output

could each represent numerous physical capacitors. Dedicate

one solid layer, usually the middle layer of the PC board, for a

ground plane and make all critical component ground

n

--------

2

CORE

–

+

6L



------------------------------------------------------------------------------------

=



-------------------------------------------------------------------

=



50

A

-------------------------------------------------------------------

=

50

100

10

20

200

500 1,000

5,000 10,000

2,000

1

2

5

10

20

50

100

200

500

1,000